Optical fiber connector with gimballed sub-assembly

ABSTRACT

An optical fiber connector sub-assembly optical fiber connector sub-assembly for an optical fiber connector includes a gimbal configured to hold a ferrule at a front portion of the connector. The gimbal is configured to provide articulated relative movement between the front portion of the connector and a rear portion of the connector such that the ferrule is isolated from movement of the rear portion of the connector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of application Ser. No. 15/887,925, filed Feb. 2,2018, pending, which claims the benefit of U.S. Provisional ApplicationNo. 62/454,032, filed Feb. 2, 2017. The disclosure of the priorapplications is hereby incorporated by reference herein in its entirety.

BACKGROUND

The present disclosure relates to an optical fiber connector, forexample an SC-style connector, and to a method of forming and using sucha connector.

The mechanical tolerances involved in terminating single mode opticalfiber are much tighter than those for multimode optical fiber.Therefore, while it is quite common for multimode optical fiber beterminated at the point of use, for example, at a user's premises or atan outside junction box, in most product applications, single modeoptical fiber is not terminated in the field. When single mode fibermust be terminated in the field, then it can take a skilled technicianbetween about 15 to 20 minutes to splice fibers together either by usinga V-groove clamp or expensive fusion welding equipment.

Single mode fiber is therefore often provided in a range of differentlengths, pre-terminated at both ends with a connector plug ready to pluginto a matching receptacle. Commonly, eight or twelve single modeoptical fibers may be bundled together in an optical fiber cable havingan outer protective tube inside of which the optical fibers run.

An example of such a connector is the “Subscriber Connector,” or SCconnector, originally developed by NTT®. SC connectors have convenientpush/pull style mating, and are approximately square in cross-sectionand with a 2.5 mm diameter ferule at the termination of the opticalfiber, surrounded by a plastic housing for protection. SC connectors areavailable in single or duplex configurations. The SC connector latchesinto a matching socket in a simple push motion. The push-pull designincludes a spring against which the ferrule slides within a plasticinner housing. This arrangement provides a reliable contact pressure atthe ferrule end and resists fiber end face contact damage of the opticalfiber during connection. The connector can be quickly disconnected byfirst pulling back an outer housing, which is slidable relative to theinner housing, to disengage a latch inside socket between the socket andthe inner housing, before pulling the optical fiber connector from thesocket. Until the latch is thus disengaged, the latch preventswithdrawal of the connector when the optical fiber cable is pulled in adirection away from the socket.

A different type of optical fiber connector is the ST type connector,which has a key that prevents rotation of the ceramic ferrule and whichconnects with a socket using a bayonet lock with an outer shell. Allsuch bayonet type optical fiber connectors are referred to herein forconvenience as “ST-type” optical fiber connectors.

An advantage of the SC connector over this type of bayonet connector isthat the connector sockets can be more closely packed, as there is noneed to get fingers fully around the connector to disengage theconnector from the socket.

Other examples of push/pull type connectors are LC connectors or MUconnectors. Often, the fiber-end is angled to reduce back reflectionsand this is usually described by adding APC (Angled Physical Contact) tothe name. All such push/pull type optical fiber connectors are forconvenience referred to herein as “SC-type” optical fiber connectors.SC-type LC or MU connectors are also known as small form factorconnectors, by virtue of having a 1.5 mm diameter ferrule and a plastichousing.

It is important to avoid bending optical fiber around curves having toosharp a bend radius, as this will increase optical losses and canpermanently damage the optical fiber. Optical fiber cables are thereforeoften routed inside a protective outer tube or conduit, which can haveminimum bend-limiting properties. Protective bend limiting conduitsnormally have an outer diameter of 8 mm or 10 mm tubes. Thecross-section of a standard SC connector has dimensions of about 7 mm×9mm, and even a small form factor SC connector is too large to fit insidethe inner diameter of a typical protective conduit.

Conventional optical fiber connectors comprise a rigid pushablestructure to allow for limited movement of the connector parts whilebeing pushed down stretches of duct. However, due to their rigidstructure, conventional optical fiber connectors suffer from signaldegradation when weight is added to the cable and the connector whilethe connector is transmitting a signal.

It may be desirable to provide an optical fiber connector with improvedsignal transmission capability. As such, it may be desirable to providean optical fiber connector with a structure that isolates the front endof the connector from the rear end of the connector such that theferrule is isolated from movement when the rear end of the connectorbends due to weight being added to the rear end.

SUMMARY

In accordance with various aspects of the disclosure,

According to various aspects, an optical fiber connector sub-assemblyfor an optical fiber connector includes a ferrule configured to hold anoptical fiber therein along an axis of the ferrule and a ferrule holderconfigured to hold the ferrule. The ferrule has an end face at which theoptical fiber is terminated, and the ferrule holder includes a base inwhich the ferrule is configured to be seated. The sub-assembly includesa gimbal that includes a sleeve and a ferrule holder carrier coupled toone another and configured to isolate a front end of the connector froma rear end of the connector such that the ferrule is isolated frommovement of the rear end of the connector. The ferrule holder carrier isconfigured to receive the ferrule holder therein.

In some aspects, the ferrule holder carrier is configured to articulaterelative to the sleeve. The sleeve may include a cylindrical portion andtwo prongs extending from a forward end of the cylindrical portion. Theferrule holder carrier may include a collar at a rearward end and abasket at a forward end, the collar including two slots that extendradially through the collar, and each of the two slots may extend abouta portion of the circumference of the collar.

According to various aspects, the two prongs and the two slots arestructured and arranged relative to one another such that the prongs areconfigured to snap into the slots. In some aspects, the prongs and theslots may be disposed symmetrically on the sleeve and the collar,respectively. In some aspects, the prongs are configured to bendradially inward when being inserted into the slots and to return towardan unstressed configuration after being inserted into the slots.

According to various aspects, after the prongs are inserted into theslots, the sleeve is configured to articulate relative to the ferruleholder carrier in an X-axis direction and a Y-axis direction that areperpendicular to each other and to an optical fiber axis.

In some aspects, the ferrule holder and the ferrule holder carrier maybe relatively moveable with respect to each other along the ferrule axisbetween limits defined by an interaction between the ferrule holdercarrier and the ferrule holder. A portion of the ferrule may lead to theend face of the ferrule projecting along the ferrule axis away from theferrule holder carrier.

In various aspects, a spring is provided between the ferrule holder andthe ferrule holder carrier and configured such that the projectingportion of the ferrule is spring-biased along the ferrule axis away fromthe ferrule holder carrier.

According to some aspects, the base of the ferrule holder has aplurality of crenellations that extend circumferentially around theferrule, the ferrule holder carrier have two arms that extend in anaxial direction through the crenellations towards the ferrule, and thetwo arms include a movement limitation feature that interacts with theferrule holder base to limit the relative movement of the ferrule holderand the ferrule holder carrier along one direction of movement along theferrule axis.

The optical fiber connector sub-assembly may be suitable for inclusionin any type of optical fiber connection, for example, an ST-type opticalfiber connector. In preferred embodiments of the invention the opticalfiber connector sub-assembly is for an SC-type optical fiber connector.

In a preferred embodiment of the invention, the movement limitationfeature is one or more projecting fingers at an end of the arms. Thearms may terminate with circumferentially extending features that engagewith the base to limit the relative movement along the ferrule axis ofthe ferrule holder away from the receiving portion of the ferruleholder. The movement limitation feature may be one or more projectingfingers that extend in a circumferential direction relative to the axisof the ferrule.

Preferably, the movement limitation feature engages with a side of thecrenellations nearest the end face of the ferrule. The crenellations mayhave alternating radially high and low regions, the movement limitationfeature engaging with a radially high region of the crenellations.

The spring may be a coil spring provided between the ferrule holder baseand the ferrule holder receiving portion, one end of said spring coilbeing engaged with a side of the crenellations furthest the end face ofthe ferrule.

Most preferably, the outermost surfaces of the ferrule holder carrierand ferrule holder, relative to the ferrule axis, lie on a commoncylindrical envelope. This help to minimize the size of the sub-assemblyin a radial direction, making it easier to insert the sub-assembly downa conduit or to pass the sub-assembly through a restricted space, priorto completing the assembly to create an SC-type optical fiber connectorassembly.

The ferrule holder may include a base having a socket in which theferrule is seated, and a hollow stem that projects axially from the basein a direction away from said projecting portion of the ferrule. Theferrule holder carrier receiving portion then extends around at least aportion of the stem and includes a feature that interacts with theferrule holder base to limit the relative movement of the ferrule holderand the ferrule holder carrier along one direction of movement along theferrule axis.

The optical fiber will normally lead to the ferrule through the stem.

The spring may be provided between the ferrule holder base and theferrule holder receiving portion. The spring may be a coil spring thatis concentrically seated around the stem of the ferrule holder.

The optical fiber base may have a plurality of crenellations that extendcircumferentially around the ferrule. The ferrule holder carrier canhave at least two arms that slidably engage with the crenellations.

The arms may terminate with circumferentially extending features thatengage with the base to limit the relative movement along the ferruleaxis of the ferrule holder away from the receiving portion of theferrule holder.

The ferrule holder and ferrule holder carrier may be adapted to beassembled by a press-fitting operation in which the ferrule holder movesalong the ferrule axis into the receiving portion of the ferrule holder.

The optical fiber will usually include a length of optical fiberextending away from the ferrule, the ferrule holder and the ferruleholder carrier. This length can be surrounded by a material forprotection and/or reinforcement, in which case the ferrule holdercarrier advantageously includes means for attaching said cladding tothis material.

According to various aspects of the disclosure, a Subscriber Connection(SC)-type optical fiber connector may include an optical fiber connectorsub-assembly, an inner housing, and an outer housing, the connectorsub-assembly being according to the disclosure, wherein: the innerhousing is fixedly connected to the ferrule holder carrier, the innerhousing comprising a portion which coaxially extends around saidprojecting portion of the ferrule to define a receptacle for a socket toreceive the projecting ferrule portion; the spring biasing means isprovided between the ferrule holder and the ferrule holder carrier sothat the projecting portion of the ferrule is spring biased along theferrule axis towards the receptacle portion of the inner housing; andthe inner housing is engaged within the outer housing, the inner housingand the outer housing being relatively moveable with respect to eachother along the ferrule axis between limits defined by an interactionbetween the inner housing and the outer housing in order to provideSC-style push/pull engagement/disengagement with a mating optical fibersocket.

The ferrule housing assembly serves as an inner housing in relation tothe outer housing in the provision of the SC-style push/pullengagement/disengagement.

The ferrule is preferably rotationally fixed with respect to the ferruleholder about the ferule axis, with the ferrule holder being rotationallyaligned by means of one or more rotational keys with respect to theouter housing so that the rotational orientation of the ferrule withrespect to the outer housing can be set during assembly of the connectorat one of one or more predefined rotational orientations.

A first rotational key may be provided between the ferrule holder andthe ferrule holder carrier. A second rotational key may then be providedbetween the ferrule holder carrier and the inner housing. The ferruleholder and the ferrule holder carrier may have aligned features whichprovide a combined rotational key between, on the one hand, the ferruleholder and the ferrule holder carrier, and, on the other hand, the innerhousing.

A further rotational key may be provided between the ferrule holdersub-assembly and the outer housing.

The ferrule holder and ferrule holder carrier may be adapted to beassembled by a press-fitting operation in which the ferrule holder movesalong the ferrule axis into the receiving portion of the ferrule holder.

The inner housing is adapted to be assembled to the ferrule holder andthe ferrule holder carrier by a press-fitting operation in which theinner housing moves along the ferrule axis over the projection portionof the ferrule towards the ferrule holder carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be further described, by way ofexample only, and with reference to the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of an exemplary prior art SCconnector;

FIG. 2 is a perspective view of the optical fiber connector sub-assemblyof FIG. 1 when assembled;

FIG. 3 is a perspective view of the SC connector of FIG. 1 whenassembled;

FIG. 4 is an exploded perspective view of an exemplary SC connector inaccordance with various aspects of the disclosure;

FIG. 5 is an exploded, side cross-sectional view of the optical fiberconnector sub-assembly of FIG. 4;

FIG. 6 is a side cross-sectional view of the optical fiber connectorsub-assembly of FIG. 4 when assembled;

FIG. 7 is a perspective view of the SC connector of FIG. 4 whenassembled;

FIG. 8 is an exploded perspective view of the optical fiber connectorsub-assembly of FIG. 4;

FIG. 9 is a perspective view of the optical fiber connector sub-assemblyof FIG. 4 when assembled; and

FIG. 10 is a perspective cross-sectional view of the optical fiberconnector sub-assembly of FIG. 4 when assembled.

DETAILED DESCRIPTION OF EMBODIMENTS

FIGS. 1 to 3 show an exemplary prior art SC connector, such as theconnector disclosed in U.S. Pat. No. 8,439,577, the disclosure of whichis incorporated herein by reference. The exemplary SC connector 1comprises an optical fiber cable 2, a ferrule housing sub-assembly 4,and an outer housing 40 to provide SC-style push/pullengagement/disengagement with a mating optical fiber socket (not shown).

The cable 2 holds a single strand of 125 μm diameter single mode opticalfiber 8, protected by primary and secondary buffering layers 10, about900 μm in diameter and an outer sheath 12, typically 3 mm to 5 mm indiameter. The optical fiber 8 is terminated by the ferrule in a mannerwell-known to those skilled in the art, and defines a ferrule axis 5which extends centrally through the SC connector 1.

The ferrule housing sub-assembly 4 includes a cylindrical ceramicferrule 14, a ferrule holder 16 in which the ferrule is seated, ahelical spring 17, a ferrule holder carrier 50, and an inner housing 20.The ferrule holder 16 has a cylindrical stem 22 which extends in anaxial direction away from the ferrule 14 towards a sleeve 136 of theferrule holder carrier 50 used to make a crimp connection around theoptical fiber cable sheathing 12. The spring 17 is seated around thestem 22 between an annular shoulder 24 on the ferrule holder 16 and asimilar annular surface 52 within a cylindrical recess 54 of the ferruleholder carrier 50. The stem 20 is slidably seated in a closely fittingbore of the ferrule holder carrier 50.

During assembly, the ferrule holder 16 and seated ferrule 14 areinserted axially into the recess 54 of the ferule holder carrier 50. Thecarrier 50 has a pair of arms 56 around a portion of the stem 22 nearestthe ferrule 14 which extend axially forwards of the stem on oppositesides of the base 15 of the ferrule holder. Two pairs of curved fingers58 are provided, each pair extending in opposite circumferentialdirections at the end of each arm 56. The fingers 58 extend transverselyto the length of the arms 56 partially around the circumference of aportion of the ferrule nearest the base 15.

The ferrule base 15 has four cycles of crenellations 62 spacedsymmetrically around the circumference of the base and which providefour corresponding channels that extend parallel to the optical fiberaxis 5. These crenellations are in the form of alternating radially high65 and low 66 cylindrically shaped regions with the circumferential andaxial extent of each of the high and low regions being the same. Thehigh and low regions are separated by steps 67 that extend in a radialdirection. The arms 56 are seated in opposite radially low regions 66 ina sliding fit with the adjacent high regions 65, and reach axiallyforward of the base 15 and crenellations 62 so that the fingers 58engage with the intervening radially high regions 65 on a side 61 of thebase 15 opposite the annular surface 24 against which the spring 17 isengaged.

The aforementioned arrangement permits a degree axial movement of theferrule holder 50, with movement being therefore limited in onedirection by the compression of the spring 17 between the two annularsurfaces 24, 52 and in the other axial direction by the contact of thefingers 58 with the radially high regions 65 of the crenellations 62 onthe base 15 of the ferrule holder 16. As can be seen from the drawings,the ferrule holder base 15 and ferrule holder carrier 50 also have acommon cylindrical outer envelope.

The inner housing 20 has a forward portion 30 that coaxially extendsaround the axially projecting ferrule 14 to define a receptacle 32 for asocket (not shown) to receive a projecting portion of the ferrule 14.

The ferrule holder 116 is free to move backwards inside the ferruleholder carrier 150 and the inner housing 120 when an end face 134 of theferrule 114 comes into contact with a similar end face (not shown) ofanother optical fiber ferrule when making an optical connection.

The ferrule holder carrier 50 has a central aperture (not shown) throughwhich the optical fiber 8 and buffering 10 pass, and has in a rear-mostportion a sleeve 36 sized to receive and be crimped to the cablesheathing 12. In some aspects, a strain-relief sleeve 38, or boot, maybe provided around the junction of the optical fiber cable 2 and theferrule housing sub-assembly 4.

An outer housing 40 is press-fitted axially over the assembled ferrulehousing sub-assembly 4. Once the inner housing 20 and outer housing 40are engaged together, the inner and outer housings are relativelymoveable with respect to each other along the ferrule axis 5 betweenlimits defined by an interaction between the inner housing 20 and theouter housing 40 provided by projections 42 on a pair of opposite sidesof the inner housing 20 and a pair of apertures 44 in the outer housing.The projections 42 and apertures 44 interact with sprung features insidea matching socket (not shown) to provide SC-style push/pull 46engagement/disengagement configured to mate with an optical fibersocket.

FIGS. 4 to 10 illustrate an exemplary SC connector 101 in accordancewith various aspects of the disclosure. The SC connector 101 comprisesan optical fiber cable 102, a ferrule housing sub-assembly 104, and anouter housing 140 to provide SC-style push/pull engagement/disengagementwith a mating optical fiber socket (not shown).

The cable 102 holds an optical fiber 108, for example, a single strandof 125 μm diameter single mode optical fiber, protected by primary andsecondary buffering layers 110, about 900 μm in diameter, and an outersheath 112, typically 3 mm to 5 mm in diameter. The optical fiber 108 isterminated by the ferrule in a manner well-known to those skilled in theart, and defines a ferrule axis 105 that extends centrally through theSC connector 101.

The ferrule housing sub-assembly 104 includes a cylindrical ceramicferrule 114, a ferrule holder 116 in which the ferrule is seated, ahelical spring 117, a gimbal 155, and an inner housing 120. The gimbal155 includes a sleeve 136 and a ferrule holder carrier 150 coupled toone another such that the ferrule holder carrier 150 is configured toarticulate relative to the sleeve 136. The sleeve 136 includes acylindrical portion 170 and two prongs 172 extending from a forward endof the cylindrical portion 170. The ferrule holder carrier 150 includesa collar 174 at a rearward end and a basket 176 at a forward end.

The collar 174 includes two slots 178 that extend radially through thecollar 178, and each of the two slots 178 extends about a portion of thecircumference of the collar 174. The two prongs 172 and two slots 178are structured and arranged relative to one another such that the prongs172 are configured to snap into the slots 178. In some aspects, theprongs 172 and the slots 178 may be disposed symmetrically on the sleeve136 and collar 174, respectively. The prongs 172 may be resilient suchthat the prongs 172 may bend radially inward when being inserted intothe slots 178 and return toward their unstressed configured after beinginserted into the slots 178.

After the prongs 172 are snapped into the slots 178, the sleeve 136 canarticulate relative to the ferrule holder carrier 150 in an X-axisdirection and a Y-axis direction that are perpendicular to each otherand to the optical fiber axis 105. As a result of this articulation, thegimbal 155 isolates a front end 190 of the connector 101 from a rear end192 of the connector 101 so that the ferrule 114 is isolated frommovement due to bending at the rear end 192 of the connector 101. Thus,the connector 101 is capable of transmitting a better signal when weightis applied to the rear end 192 of the connector 191 that causes bendingof the rear end 192.

As best illustrated in FIG. 9, the prongs 172 and the slots 178 areconfigured such that the sleeve 136 and the ferrule holder carrier 150are rotatably fixed to one another (i.e., are not rotatable relative toone another) when the prongs 172 are inserted into the slots 178. Thebasket 176 and the collar 174 may also include longitudinal slots 180,182 along the lengths of their outer surfaces that are keyed toprojections 126 on an inner surface of the inner housing 120 to preventthe ferrule holder carrier 150 from rotating relative to the innerhousing 120.

The ferrule holder 116 has a cylindrical stem 122 which extends in anaxial direction away from the ferrule 114 towards the ferrule holdercarrier 150 and the sleeve 136, which is used to make a crimp connectionaround the optical fiber cable sheathing 112. The spring 117 is seatedaround the stem 122 between an annular shoulder 124 on the ferruleholder 116 and a similar annular surface 152 within a cylindrical recess154 of the ferrule holder carrier 150. The stem 120 is slidably seatedin a closely fitting bore of the ferrule holder carrier 150.

During assembly, the ferrule holder 116 and seated ferrule 114 areinserted axially into the recess 154 of the ferule holder carrier 150.The carrier 150 has a pair of arms 156 around a portion of the stem 122nearest the ferrule 114 which extend axially forwards of the stem onopposite sides of the base 115 of the ferrule holder 116. Two pairs ofcurved fingers 158 are provided, each pair extending in oppositecircumferential directions at the end of each arm 156. The fingers 158extend transversely to the length of the arms 156 partially around thecircumference of a portion of the ferrule 114 nearest the base 115.

The ferrule base 115 has four cycles of crenellations 162 spacedsymmetrically around the circumference of the base and which providefour corresponding channels that extend parallel to the optical fiberaxis 105. These crenellations 162 are in the form of alternatingradially high 165 and low 166 cylindrically shaped regions with thecircumferential and axial extent of each of the high 165 and low 166regions being the same. The high 165 and low 166 regions are separatedby steps 167 that extend in a radial direction. The arms 156 are seatedin opposite radially low regions 166 in a sliding fit with the adjacenthigh regions 165, and reach axially forward of the base 115 andcrenellations 162 so that the fingers 158 engage with the interveningradially high regions 165 on a side 161 of the base 115 opposite theannular surface 124 against which the spring 117 is engaged.

The aforementioned arrangement permits a degree axial movement of theferrule holder 150, with movement being therefore limited in onedirection by the compression of the spring 117 between the two annularsurfaces 124, 152 and in the other axial direction by the contact of thefingers 158 with the radially high regions 165 of the crenellations 162on the base 115 of the ferrule holder 116. As can be seen from thedrawings, the ferrule holder base 115 and ferrule holder carrier 150also have a common cylindrical outer envelope.

The inner housing 120 has a forward portion 130 that coaxially extendsaround the axially projecting ferrule 114 to define a receptacle 132 fora socket (not shown) to receive a projecting portion of the ferrule 114.

The ferrule holder 116 is free to move backwards inside the ferruleholder carrier 150 and the inner housing 120 when an end face 134 of theferrule 114 comes into contact with a similar end face (not shown) ofanother optical fiber ferrule when making an optical connection.

The ferrule holder carrier 150 has a central aperture (not shown)through which the optical fiber 108 and buffering 110 pass, and has in arear-most portion the sleeve 136 configured to receive and be crimped tothe cable sheathing 112. In some aspects, a strain-relief sleeve 138,for example, a boot, may be provided around the junction of the opticalfiber cable 102 and the ferrule housing sub-assembly 104.

An outer housing 140 is press-fitted axially over the assembled ferrulehousing sub-assembly 104. Once the inner housing 120 and outer housing140 are engaged together, the inner and outer housings are relativelymoveable with respect to each other along the ferrule axis 105 betweenlimits defined by an interaction between the inner housing 120 and theouter housing 140 provided by projections 142 on a pair of oppositesides of the inner housing 120 and a pair of apertures 144 in the outerhousing. The projections 142 and apertures 144 interact with sprungfeatures inside a matching socket (not shown) to provide SC-stylepush/pull 146 engagement/disengagement configured to mate with anoptical fiber socket.

The rotational orientation of the ferrule holder carrier 150 may be setat one of four orientations relative to the ferrule 114 in the ferruleholder 116 owing to the seating of the arms 156 in the crenellations. Inthis way, a first rotational key is provided between the ferrule holder116 and the ferrule holder carrier 150 such that the ferrule holder 116and the ferrule holder carrier 150 are rotatably fixed to one another(i.e., are not rotatable relative to one another).

The optical fiber 108 is therefore terminated in a sub-assembly referredto herein as an optical fiber connector sub-assembly 160. Duringassembly of the optical fiber connector sub-assembly 160, the arms 156and the fingers 158, which each have a chamfered taper 164 on an innerforwards surface, flex outwardly over the base 115 of the ferrule holder114 until the fingers 158 snap radially inwards into engagement with theforwards surface 161 of the ferrule holder base 115.

In both cases, the resulting optical fiber connector sub-assembly 160 istherefore mechanically whole or integral, both as regards the componentsforming the sub-assembly and as regards the mechanical connection of thesub-assembly to the optical fiber cable 102. The sub-assembly cannotcome apart without first prizing the fingers 158 back over the feruleholder base 115. The ferrule holder carrier 150 has an outer diameterwhich is preferably no more than that of the widest portion of theferrule holder 114, i.e. the ferrule holder base 115.

After the insertion has been performed, the assembly of the SC-typeoptical fiber connector is completed as follows. The inner housing 120is inserted in an axial direction over the projecting ferrule 114 andsurrounding ferrule holder carrier 150. The external shape of the innerhousing 120 where this interacts with the outer housing 140 is the sameas with conventional connectors. The outer housing 140 therefore issnap-fitted over the inner housing 120, after which the SC-typeconnector 101 is fully compatible with conventional connectors andconventional optical fiber sockets.

It should be noted that although the specific example described aboverelate to an SC-type connector, the optical fiber connector sub-assemblycan be adapted for use with other types of optical fiber connectorsystems, for example the ST-type connectors.

The disclosure therefore provides a convenient optical fiber connectorand optical fiber communication system and method for providing such asystem.

Additional embodiments include any one of the embodiments describedabove, where one or more of its components, functionalities orstructures is interchanged with, replaced by or augmented by one or moreof the components, functionalities, or structures of a differentembodiment described above.

It should be understood that various changes and modifications to theembodiments described herein will be apparent to those skilled in theart. Such changes and modifications can be made without departing fromthe spirit and scope of the present disclosure and without diminishingits intended advantages. It is therefore intended that such changes andmodifications be covered by the appended claims.

Although several embodiments of the disclosure have been disclosed inthe foregoing specification, it is understood by those skilled in theart that many modifications and other embodiments of the disclosure willcome to mind to which the disclosure pertains, having the benefit of theteaching presented in the foregoing description and associated drawings.It is thus understood that the disclosure is not limited to the specificembodiments disclosed herein above, and that many modifications andother embodiments are intended to be included within the scope of theappended claims. Moreover, although specific terms are employed herein,as well as in the claims which follow, they are used only in a genericand descriptive sense, and not for the purposes of limiting the presentdisclosure, nor the claims which follow.

The invention claimed is:
 1. An optical fiber connector sub-assembly foran optical fiber connector, comprising: a gimbal including a ferruleholder carrier portion configured to hold a ferrule and a sleeve portiondisposed rearward of the ferrule holder carrier portion along an axis ofthe connector, wherein the gimbal is configured to provide articulatedrelative movement between the sleeve portion and the ferrule holdercarrier portion, and wherein the sleeve portion and the ferrule holdercarrier portion are configured to be rotatably fixed to one another. 2.The optical fiber connector sub-assembly of claim 1, wherein the sleeveportion and the ferrule holder carrier portion are configured tomechanically isolate a front portion of the connector from a rearportion of the connector.
 3. The optical fiber connector sub-assembly ofclaim 2, wherein the ferrule is isolated from movement of the rearportion of the connector.
 4. The optical fiber connector sub-assembly ofclaim 3, wherein the sleeve portion and the ferrule holder carrierportion are configured to articulate relative to one another in anX-axis direction and a Y-axis direction that are perpendicular to eachother and to the connector axis.
 5. The optical fiber connectorsub-assembly of claim 4, further comprising a ferrule holder configuredto hold the ferrule, wherein the ferrule holder carrier portion isconfigured to hold the ferrule holder, and wherein ferrule holder andthe ferrule holder carrier portion are configured to move relative toone another along the connector axis between limits defined by aninteraction between the ferrule holder carrier portion and the ferruleholder.
 6. A Subscriber Connection (SC)-type optical fiber connectorcomprising an optical fiber connector sub-assembly, an inner housing,and an outer housing, the connector sub-assembly being as claimed inclaim 5, wherein the inner housing is configured to be fixedly connectedto the ferrule holder carrier portion and to define a receptacle for asocket to receive a projecting portion of the ferrule; and wherein theinner housing is configured to be engaged within the outer housing, theinner housing and the outer housing being configured to move relative toeach other along the connector axis between limits defined by aninteraction between the inner housing and the outer housing in order toprovide SC-style push/pull engagement/disengagement with a matingoptical fiber socket.
 7. The SC-type optical fiber connector of claim 6,wherein the ferrule is configured to be rotationally fixed with respectto the ferrule holder about the connector axis, and wherein the ferruleholder is configured to be rotationally aligned with respect to theouter housing so that the rotational orientation of the ferrule withrespect to the outer housing can be set during assembly of the connectorat one of one or more predefined rotational orientations.
 8. The SC-typeoptical fiber connector of claim 7, wherein a first rotational key isprovided between the ferrule holder and the ferrule holder carrierportion and a second rotational key is provided between the ferruleholder carrier portion and the inner housing.